It is known to use a Monte Carlo method for calculating an x-ray dose distribution within a person during a computed tomography examination, wherein the Monte Carlo method uses x-ray parameters defining x-ray properties like the position, orientation and intensity of x-rays and a model of the person defining the influence on traversing x-rays by the person during the computed tomography examination. A corresponding Monte Carlo method is disclosed, for instance, in the article “Radiation Exposure to Patients in a Multicenter Coronary Angiography Trial (CORE 64)” by J. Geleijns et al., Medical Physics and Informatics, volume 196, number 5, pages 1126 to 1132 (2011). This Monte Carlo based calculation of the x-ray dose distribution within the person for a computed tomography examination requires high computational efforts and takes therefore a relatively long time.